一直

When the adverb “ 一直” is used to indicate space, it expresses the idea of going continuously in one direction, for example,
请一直往前走。
你一直往东开，到街心花园再往南拐，然后一直往南就到了。
The adverb “ 一直” is used to indicate either that an action continues without interruption or that a state remains unchanged within the mentioned time period, for example,
从上个世纪70年代以来，中国一直在实行计划生育政策。
这两个月大家一直很忙。
他一直要学到放暑假。
雨一直下了两天两夜。